package com.singleton.type3;

/**
 * @author 薛虎
 * @date 2020/12/16 8:50
 * 懒汉式(线程不安全)
 */
public class SingletonTest03 {
    public static void main(String[] args) {
        System.out.println("懒汉式(线程不安全的)");
        //测试
        Singleton singleton = Singleton.getInstance();
        Singleton singleton1 = Singleton.getInstance();

        System.out.println(singleton == singleton1);
    }
}


class Singleton {

    private static Singleton instance;

    private Singleton() {
    }

    //提供一个静态的公有方法,当使用到该方法时,才去创建instance
    //即懒汉式
    public static Singleton getInstance() {
        if (instance == null) {
            instance = new Singleton();
        }
        return instance;
    }
}
